Cart frame



FIG. 1 is a left side elevational view of a cart frame showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a rear elevational view thereof; and

FIG. 6 is a right side elevational view thereof.

The broken lines shown in FIGS. 1 through 6 are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a cart frame, as shown and described. 